linux-imx

/*

 * Watchdog driver for Technologic Systems TS-72xx based SBCs

 * (TS-7200, TS-7250 and TS-7260). These boards have external

 * glue logic CPLD chip, which includes programmable watchdog

 * timer.

 *

 * Copyright (c) 2009 Mika Westerberg <mika.westerberg@iki.fi>

 *

 * This driver is based on ep93xx_wdt and wm831x_wdt drivers.

 *

 * This file is licensed under the terms of the GNU General Public

 * License version 2. This program is licensed "as is" without any

 * warranty of any kind, whether express or implied.

 */

​

#include <linux/platform_device.h>

#include <linux/module.h>

#include <linux/watchdog.h>

#include <linux/io.h>

​

#define TS72XX_WDT_DEFAULT_TIMEOUT  30

​

static int timeout;

module_param(timeout, int, 0);

MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds.");

​

static bool nowayout = WATCHDOG_NOWAYOUT;

module_param(nowayout, bool, 0);

MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");

​

/* priv->control_reg */

#define TS72XX_WDT_CTRL_DISABLE     0x00

#define TS72XX_WDT_CTRL_250MS       0x01

#define TS72XX_WDT_CTRL_500MS       0x02

#define TS72XX_WDT_CTRL_1SEC        0x03

#define TS72XX_WDT_CTRL_RESERVED    0x04

#define TS72XX_WDT_CTRL_2SEC        0x05

#define TS72XX_WDT_CTRL_4SEC        0x06

#define TS72XX_WDT_CTRL_8SEC        0x07

​

/* priv->feed_reg */

#define TS72XX_WDT_FEED_VAL     0x05

​

struct ts72xx_wdt_priv {

    void __iomem    *control_reg;

    void __iomem    *feed_reg;

    struct watchdog_device wdd;

    unsigned char regval;

};

​

static int ts72xx_wdt_start(struct watchdog_device *wdd)

{

    struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);

​

    writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg);

    writeb(priv->regval, priv->control_reg);

​

    return 0;

}

​

static int ts72xx_wdt_stop(struct watchdog_device *wdd)

{

    struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);

​

    writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg);

    writeb(TS72XX_WDT_CTRL_DISABLE, priv->control_reg);

​

    return 0;

}

​

static int ts72xx_wdt_ping(struct watchdog_device *wdd)

{

    struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);

​

    writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg);

​

    return 0;

}

​

static int ts72xx_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)

{

    struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);

​

    if (to == 1) {

        priv->regval = TS72XX_WDT_CTRL_1SEC;

    } else if (to == 2) {

        priv->regval = TS72XX_WDT_CTRL_2SEC;

    } else if (to <= 4) {

        priv->regval = TS72XX_WDT_CTRL_4SEC;

        to = 4;

    } else {

        priv->regval = TS72XX_WDT_CTRL_8SEC;